Two passenger coaches collided on a highway near Zibo in east China\'s Shandong Province on Sunday, leaving 13 dead and nine seriously injured, local traffic police said. A passenger coach run by the Shanghe County Long-distance Transportation Company of Jinan City hit a sedan at 11:44 a.m., then broke through median barriers and collided with another coach traveling in the opposite lane, said Wang Jiguo, chief of the Zibo Traffic Police Brigade. The second coach, run by the Jinan-based Lushun Tourist Automobile Company, rolled over into a trench alongside the highway, which links Qinghai to Yinchuan. Six people died on the spot. Seven died in hospital with another nine seriously injured, Wang said. The cause of the accident is under investigation, Wang said.